But he stressed that any package put forward to help them must be "affordable".

His comments came after four pensioners today won an unprecedented High Court action over the collapse of their final salary pension schemes.

The four - Henry Bradley, Robin Duncan, Andrew Parr and Thomas Waugh - were among tens of thousands of victims who lost all or part of their pensions.

Mr Justice Bean ruled at London's High Court that Pensions Minister John Hutton had no power to reject Parliamentary ombudsman Ann Abraham's report that the Government was guilty of maladministration and should consider offering victims compensation.

Mr Cameron said 125,000 people who paid into company pension schemes had seen them collapse and been left with "little or nothing".

Today, "the Government was defeated in the courts and ordered to look again at how it's responded to the real crisis at the heart of our pension system".

He asked: "Do you agree that there's real strength of feeling on all sides of the House that these people have not been treated fairly?

"And will you now look at working - on a cross party basis - at finding an affordable and sustainable basis?"

As Labour MPs jeered, he added: "Let's sort this out."

Mr Blair replied: "Of course, I'm very happy to work on any basis with other parties in order to try and provide for pensioners.

"For the very first time, we now have a compensation programme in place worth hundreds of millions of pounds for those who have lost their pensions, in addition to the considerable extra support given to pensioners.

"We are still studying the exact terms of this judgment. As I understand it, although it found problems with some of the leaflets issued both by the previous government and this government, nonetheless it did not actually find there was a causal link between that and the losses that were suffered.

"But I entirely agree, it's a terrible situation for those people who have lost their pensions.

"But we must make sure that any package we put forward is affordable."

Mr Cameron said it was becoming increasingly clear that the assistance scheme was not working properly.

"Of the 125,000 people left with little or nothing, a year after the Ombudsman reported, only 900 have received any money.

"That is completely inadequate. Will you confirm those figures for us?"

Mr Blair said: "I think the overall amount of money that will be in the (assistance) scheme is somewhere in the region of £1.8 billion over the years to come.

"That is a huge commitment on the part of the Government. Absolutely nothing was in place before we did this.

"However, I agree, we have to see how we help people in this situation. But I assume you are not saying that we can give a guarantee that the Government can stand behind the collapse of any pension scheme.

"That would be a huge commitment - billions and billions of pounds over the years.

"There is inevitably going to be a situation where the commitment we give to people who lose their pensions is going to be limited.

"But £1.8 billion is quite a generous commitment."

Mr Cameron told him: "The point is the money is not getting through to the people who need it.

"Given that the financial assistance scheme isn't working and an increasing number of pension experts recognise this, will you at least look at ideas that wouldn't cost taxpayers' money - such as pooling the scheme funds, such as rolling the administration of the financial assistance scheme that isn't working properly into the pension protection fund.

"Will you also look at unclaimed pension assets.

"The fact is these pensioners have lost their money under your watch and you've got time now to do something about it.

"These people lost their pensions partly because of the £5 billion pension raid that the Chancellor's carried out every year.

"You can use your last few months in office to grandstand or do something for these people.

Will you meet with the pensioners and with their representatives, and on a cross party basis, sort this out?"

Mr Blair branded the Opposition leader's question a "pretty good example of grandstanding".

He added: "I thought you had begun this question not just to make a political point. But the fact is the pension mis-selling under the previous government was absolutely legendary.

"The only compensation is the compensation we have given.

"It's not true to say the assistance scheme is not working. It's for people who are going to become pensioners in the future.

"We are perfectly prepared to sit down and look at what more we can do. But in the end it will come down to money.

"The other day your shadow chancellor (George Osborne) was asked in specific terms whether he would commit more money to pensions and said there are people in the Conservative party who are asking us to put more money into pensions - 'we have got to resist these demands'."

Labour backbenchers cheered in delight as Mr Cameron remained in his seat and the questioning moved on.